Characterization of T-cell receptor transgenic mice recognizing immunodominant HLA-DQ2.5-restricted gluten epitopes.

We created a TCR transgenic mouse with CD4+ T cells recognizing the immunodominant DQ2.5-glia-ω2 gluten epitope. We show that these cells respond to deamidated gluten feed in vivo and compare them to previously published α2- and γ1-specific mice. These mice may help enlighten key aspects of celiac disease pathogenesis.

Lindstad CB ，Qiao SW ，Johannesen MK ，Fugger L ，Sollid LM ，du Pré MF ... -  《-》

Resistance to celiac disease in humanized HLA-DR3-DQ2-transgenic mice expressing specific anti-gliadin CD4+ T cells.

de Kauwe AL ，Chen Z ，Anderson RP ，Keech CL ，Price JD ，Wijburg O ，Jackson DC ，Ladhams J ，Allison J ，McCluskey J ... -  《-》

TCR sequencing of single cells reactive to DQ2.5-glia-α2 and DQ2.5-glia-ω2 reveals clonal expansion and epitope-specific V-gene usage.

Dahal-Koirala S ，Risnes LF ，Christophersen A ，Sarna VK ，Lundin KE ，Sollid LM ，Qiao SW ... -  《-》

Comprehensive Analysis of CDR3 Sequences in Gluten-Specific T-Cell Receptors Reveals a Dominant R-Motif and Several New Minor Motifs.

Gluten-specific CD4+ T cells are drivers of celiac disease (CeD). Previous studies of gluten-specific T-cell receptor (TCR) repertoires have found public TCRs shared across multiple individuals, biased usage of particular V-genes and conserved CDR3 motifs. The CDR3 motifs within the gluten-specific TCR repertoire, however, have not been systematically investigated. In the current study, we analyzed the largest TCR database of gluten-specific CD4+ T cells studied so far consisting of TCRs of 3122 clonotypes from 63 CeD patients. We established a TCR database from CD4+ T cells isolated with a mix of HLA-DQ2.5:gluten tetramers representing four immunodominant gluten epitopes. In an unbiased fashion we searched by hierarchical clustering for common CDR3 motifs among 2764 clonotypes. We identified multiple CDR3α, CDR3β, and paired CDR3α:CDR3β motif candidates. Among these, a previously known conserved CDR3β R-motif used by TRAV26-1/TRBV7-2 TCRs specific for the DQ2.5-glia-α2 epitope was the most prominent motif. Furthermore, we identified the epitope specificity of altogether 16 new CDR3α:CDR3β motifs by comparing with TCR sequences of 231 T-cell clones with known specificity and TCR sequences of cells sorted with single HLA-DQ2.5:gluten tetramers. We identified 325 public TCRα and TCRβ sequences of which 145, 102 and 78 belonged to TCRα, TCRβ and paired TCRαβ sequences, respectively. While the number of public sequences was depended on the number of clonotypes in each patient, we found that the proportion of public clonotypes from the gluten-specific TCR repertoire of given CeD patients appeared to be stable (median 37%). Taken together, we here demonstrate that the TCR repertoire of CD4+ T cells specific to immunodominant gluten epitopes in CeD is diverse, yet there is clearly biased V-gene usage, presence of public TCRs and existence of conserved motifs of which R-motif is the most prominent.

Dahal-Koirala S ，Risnes LF ，Neumann RS ，Christophersen A ，Lundin KEA ，Sandve GK ，Qiao SW ，Sollid LM ... -  《Frontiers in Immunology》

Generation of an HLA-DQ2.5 Knock-In Mouse.

The human MHC class II molecule HLA-DQ2.5 is implicated in multiple autoimmune disorders, including celiac disease, type 1 diabetes, and systemic lupus erythematosus. The pathogenic contribution of HLA-DQ2.5 in many of these disorders is not fully understood. There is thus a need for an HLA-DQ2.5 humanized mouse model with physiological expression of this MHC molecule that can be integrated into disease models. In this article, we report the generation of an HLA-DQ2.5 knock-in mouse strain on a C57BL/6 background in which sequences encoding the extracellular moieties of mouse MHC class II H2-IAa and H2-IAb1 have been replaced with those of HLA-DQA1*05:01 and HLA-DQB1*02:01 In heterozygous knock-in mice, the expression of HLA-DQ2.5 is superimposable with the expression of H2-IA. This was not the case in a regular untargeted HLA-DQ2.5 transgenic mouse. HLA-DQ2.5 in the knock-in animals is functional for T cell development and for Ag presentation to HLA-DQ2.5-restricted and gluten-specific T cells. Because C57BL/6 mice do not express H2-IEa, the only functional MHC class II molecule in homozygous HLA-DQ2.5 knock-in mice is the knock-in gene product. This alleviates the need for crossing with MHC class II knockout mice to study the isolated function of the MHC transgene. Our novel mouse strain provides an important tool to study the involvement of HLA-DQ2.5 in models of diseases with association to this HLA allotype.

Dewan AE ，Koentgen F ，Johannesen MK ，du Pre MF ，Sollid LM ... -  《-》